Large crushing plants typically have an overhead feed structure which dumps material to be crushed onto crushing rolls located below the feed structure. The crushing rolls are preferably supported by a stationary framework which assures the ability to withstand the forces involved in the crushing of large pieces of material such as stone and coal. On the other hand, accessibility to and movability of the crushing rolls to inspect and remove them for maintenance purposes is also necessary.
As a result of the need for removal of the crushing rolls, various compromise arrangements between stationary and movable mounting of the crushing rolls have been used in commercial installations. In one common type of such crusher construction, the crushing rolls on one side of the crushing apparatus are mounted on a stationary frame and the crushing rolls on the other side are mounted on a movable frame and are therefore referred to as movable rolls. During normal crushing operation, the movable crushing rolls on the movable frame are positioned adjacent the stationarily mounted rolls. To remove the movable crushing rolls from the crushing plant, the movable frame is moved away from the stationary frame and out from beneath the overhead feed structure. This permits access to the crushing rolls carried on the movable frame and their removal by a suitable hoist. The stationary rolls may be detached from their support and moved through the space resulting from the movement of the movable frame to a position where the stationary rolls may also be lifted and removed by a hoist. However, a serious drawback of this crushing apparatus is that it is very difficult to move the stationary rolls, which may weigh two to three tons, underneath the overhead feed structure to a position where they can be lifted and removed.
It is accordingly a general object of this invention to provide a crushing roll removal apparatus and method which eliminates the aforesaid difficulty and permits relatively easy and quick removal of stationary crushing rolls in a crushing plant.